Migration and Business Cycle Dynamics
Christie Smith1 Christoph Thoenissen2 Treasury Guest Lecture 18 April 2018
1Reserve Bank of New Zealand 2University of Sheffield
Migration and Business Cycle Dynamics Christie Smith 1 Christoph - - PowerPoint PPT Presentation
Migration and Business Cycle Dynamics Christie Smith 1 Christoph Thoenissen 2 Treasury Guest Lecture 18 April 2018 1 Reserve Bank of New Zealand 2 University of Sheffield Disclaimer The views expressed in this paper are solely the responsibility
1Reserve Bank of New Zealand 2University of Sheffield
◮ In recent years, 2015 in Europe, and 2012 onwards in New Zealand, we have seen
◮ The recent increase in net migration has certainly had a political impact. The
◮ The economics profession has, of course, been paying attention to migration as a
◮ For a good survey of the existing literature see Kerr and Kerr (2011, NBER) ◮ To the best of our knowledge this is amongst the first papers to analyse the role
◮ The aim of our paper is to analyse the macroeconomic consequences of shocks to
◮ Are the macroeconomic consequences of migration as bad as popular opinion
◮ Surprising lack of literature on the macroeconomics of migration.
◮ Mandelman and Zlate (2012, JME) ‘Immigration, remittances and the business
◮ McDonald (2013), ‘Migration and the housing market’ AN/RBNZ. Documents
◮ Vehbi (2016), ‘The macroeconomic impact of the age composition of migration’,
◮ Armstrong and McDonald (2016), ‘Why the drivers of migration matter for the
◮ Clemens and Hart (2016, mimeo) ‘Migration, unemployment and the business
◮ Weiske (2017, mimeo) ‘On the Macroeconomic Effects of Immigration: A VAR
◮ Furlanetto and Robstad (2016, mimeo) ‘Immigration and the macroeconomy:
◮ Two main objectives of our work: (i) understand the transmission mechanism of
◮ Apart from the effects of migration shocks on the usual components of GDP, we
◮ To answer these questions, we build a small open economy DSGE model with
◮ We check for the robustness of our results by using a less restrictive SVAR
◮ Adding migration to dynamic business cycle models is relatively straight forward:
◮ Small Open Economy model → allows us to treat migration as exogenous. We
◮ Economy is price taker in international goods and factor markets. Open economy
◮ Households use their time endowment for leisure, work, and skill accumulation. ◮ Accumulated skills/human capital differentiates migrants from ‘natural’
◮ Economy consists of three sectors: household sector, traded goods
◮ Firms produce domestic goods with capital, whose intensity of use they can vary,
◮ Houses are built using land, effective labour, and final goods. ◮ Other useful open economy features: PPP deviations via consumption home-bias;
◮ Households have preferences over consumption, housing, hours of work and hours
◮ Final consumption goods are an aggregate of home and foreign-produced
1 θ
θ
1 θ
θ
θ−1
◮ Households maximise expected utility subject to the flow budget constraint:
◮ Human capital is produced by combining existing human capital with time spent
◮ The stock of human capital, denoted dt, evolves according the following law of
Household’s FOCs
◮ Households supply firms with effective labour, defined as ntdt−1
◮ The opportunity cost of investing in human capital is borne exclusively by the
◮ Households divide total effective labour, ent, between the goods producing sector,
◮ Firms maximise profits:
◮ Notable features: firms employ effective labour, can vary the degree of capacity
Firms’ FOCs
◮ Our housing and construction sector is based on Iacoviello (2005, AER). Housing
◮ Profits in the construction sector at time t are defined as πH
◮ New houses are produced using land, effective labour and home-produced traded
◮ FOCs for effective hours, land usage and intermediate inputs:
◮ Market clearing implies that the supply of new houses equals the net increase in
◮ The total supply of land is fixed, which would implies that net migration
◮ Indeed, that is the main effect of migration, it dilutes stock on a per capita basis.
◮ From a model solution point of view, we need a well-defined steady state around
◮ Hence, we assume that whereas the total supply of land is fixed, the supply of
◮ Market clearing condition for home-produced goods:
◮ Export demand:
◮ Current account:
◮ Closing the model via a debt elastic interest rate:
◮ There are 7 AR(1) shocks driving the model: technology; housing technology;
◮ The migration process is defined as vt ≡ ln (Nt/Nt−1) ◮ Every observable has an obvious ‘driver’ e.g. GDP and TFP, Investment and MEI,
◮ Migration and population growth dilute stocks on a per capita basis. Unlike
◮ To illustrate the effect of migrants arriving with human capital, consider the
◮ Unskilled migration reduces the per capital stock of human capital in the
◮ We use quarterly data for net working-age migration, GDP, private consumption,
◮ All data series are divided by working age population and, apart from migration
◮ We focus on New Zealand, because of (a) the availability of high quality
◮ Very high net migration during the last 3-5 years - ca. 70k per annum –
◮ NZ arrivals/departures predominantly via airports, hence excellent data coverage.
◮ We match our seven data series to seven equivalent variables in the model. ◮ Two of our observables correspond directly to exogenous shock processes [World
◮ The remaining parameters have standard priors taken from the relevant literature. ◮ Bayesian estimation implemented via two MCMCs chains of 2,000,000 draws.
Parameter Description Prior Mean Std Dev
(5% 95%) α Share of capital N 0.330 0.010 0.330 0.314 0.346 αh Share of land in housing N 0.700 0.050 0.614 0.561 0.667 δ Depreciation rate capital N 2.500 0.500 2.748 1.944 3.538 η Frisch elasticity Γ 2.000 0.750 3.733 2.211 5.251 θ
N 1.000 0.250 2.550 2.498 2.590 γ Openness β 0.300 0.010 0.337 0.321 0.353 acu Capacity-U curvature β 0.500 0.150 0.669 0.479 0.865 ac Investment adjustment costs N 4.000 1.500 6.313 4.433 8.131 φb × 100 Bond adjustment costs Γ−1 1.000 5.000 0.205 0.152 0.256 ρa Persistence tech. β 0.500 0.200 0.762 0.710 0.814 ρah Persistence housing tech. β 0.500 0.200 0.718 0.613 0.826 ρy Persistence foreign demand. β 0.886 0.010 0.887 0.871 0.903 ρj Persistence housing pref. β 0.500 0.200 0.860 0.806 0.917 ρjc Persistence consumption pref. β 0.500 0.200 0.830 0.780 0.879 ρi Persistence investment-specific β 0.500 0.150 0.272 0.145 0.397 ρv Persistence migration β 0.890 0.010 0.890 0.874 0.906 ǫa Std dev. tech. Γ−1 0.004 1.500 0.030 0.026 0.034 ǫh Std dev. housing tech. Γ−1 0.005 1.500 0.038 0.032 0.043 ǫyf Std dev. foreign demand Γ−1 0.007 1.500 0.007 0.006 0.008 ǫj Std dev. housing pref. Γ−1 0.005 0.500 0.535 0.335 0.728 ǫi Std dev. investment-specific Γ−1 0.005 1.500 0.366 0.244 0.483 ǫjc Std dev. consumption pref. Γ−1 0.004 1.500 0.034 0.030 0.039 ǫv Std dev. migration Γ−1 0.001 1.500 0.001 0.001 0.001 Calibrated χ Relative human cap of migrants 1.85 δh × 100 Depreciation rate housing 1 β Discount rate 1/1.01 δd Depreciation rate human cap. 0.01 φs Skill accumulation 0.5 ¯ j Steady-state j 0.7 n + s Hours worked + training 1/3 ξm Share of traded goods in housing 0.1 H/c H - C ratio 0.12
◮ Standard/plausible parameter estimates throughout. ◮ Migration shocks are fairly persistent with an AR(1) coefficient of 0.89, but not
◮ Key calibrated parameter of note is χ, the relative level of human capital of
5 10 15 20 1 2 3 4 ×10-3 Output 5 10 15 20 0.5 1 1.5 2 2.5 ×10-3 Consumption 5 10 15 20 0.005 0.01 Investment 5 10 15 20 2 4 6 8 ×10-3 Effective hours 5 10 15 20
Bonds 5 10 15 20
5 10 ×10-4 Terms of trade 5 10 15 20
0 ×10-4 Wage 5 10 15 20 1 2 3 4 5 ×10-4 Migration 5 10 15 20 1 2 3 4 5 ×10-3 MPK 5 10 15 20
0 ×10-3 Housing per capita 5 10 15 20 1 2 3 ×10-3 Price of housing 5 10 15 20 1 2 3 ×10-3 Construction 5 10 15 20
0 ×10-3 Skill acquisition 5 10 15 20 1 2 3 ×10-3 Human capital
◮ An increase in net migration is expansionary. ◮ Per capita GDP, consumption, investment, residential investment rise following
◮ The terms of trade/real exchange rate appreciates following a net migration
◮ Net migration raises the return on fixed assets, eg physical capital and housing
◮ When migrants are more skilled than locals, there is a gain in the average human
◮ Because of (a) the appreciation and (b) the increase in the marginal product of
◮ The increase in utilisation is key to raising output per head. ◮ An increase in net migration raises real house prices and residential investment. ◮ Rise in relative price of houses shifts factors of production out of the goods
◮ This effect is partially offset by an increase in the utilisation rate of installed
◮ The investment boom and real appreciation lead to a trade deficit.
Shocks Observables ǫa ǫh ǫyf ǫj ǫi ǫjc ǫv GDP 0.36 0.04 0.00 0.35 0.04 0.02 0.19 [0.22, 0.49] [0.02, 0.06] [0.00, 0.00] [0.12, 0.56] [0.01, 0.07] [0.01, 0.02] [0.11, 0.27] Investment 0.12 0.00 0.00 0.01 0.70 0.00 0.17 [0.05, 0.18] [0.00, 0.00] [0.00, 0.00] [0.00, 0.01] [0.55, 0.85] [0.00, 0.00] [0.07, 0.27] Residential Invest. 0.00 0.46 0.00 0.50 0.00 0.01 0.03 [0.00, 0.00] [0.23, 0.72] [0.00, 0.00] [0.25, 0.76] [0.00, 0.00] [0.00, 0.01] [0.01, 0.04] Consumption 0.24 0.00 0.00 0.02 0.07 0.56 0.12 [0.18, 0.29] [0.00, 0.00] [0.00, 0.00] [0.00, 0.04] [0.04, 0.10] [0.48, 0.62] [0.09, 0.15] Real House Prices 0.05 0.00 0.00 0.88 0.01 0.02 0.04 [0.01, 0.08] [0.00, 0.01] [0.00, 0.00] [0.79, 0.98] [0.00, 0.02] [0.00, 0.03] [0.01, 0.07]
◮ When looked at through the prism of our DSGE model migration shocks matter,
◮ They account for about 1/5 of the variance of GDP, 17 - 12% of investment and
◮ Predictably, world demand shocks do not matter – the dynamics of the terms of
◮ Residential investment is explained in roughly equal proportions by supply and
◮ House prices are mainly explained by housing demand shocks unrelated to
◮ Housing demand shocks also affect GDP, as do the usual TFP shocks in the
◮ To what extent do the results hinge on the relative degree of human capital of
◮ Does the general picture hold using a much less restrictive SVAR model?
◮ As a sensitivity check, we set χ = 1 which implies that migrants have the same
◮ We find almost an identical set of estimated parameters, yet a much reduced role
Shocks Observables ǫa ǫh ǫyf ǫj ǫi ǫjc ǫv GDP 0.42 0.05 0.00 0.38 0.13 0.01 0.00 [0.25, 0.58] [0.03, 0.08] [0.00, 0.00] [0.16, 0.59] [0.04, 0.22] [0.01, 0.02] [0.00, 0.01] Investment 0.06 0.00 0.00 0.00 0.92 0.00 0.02 [0.02, 0.10] [0.00, 0.00] [0.00, 0.00] [0.00, 0.01] [0.86, 0.97] [0.00, 0.00] [0.00, 0.03]
0.00 0.50 0.00 0.48 0.01 0.01 0.01 [0.00, 0.00] [0.27, 0.75] [0.00, 0.00] [0.24, 0.72] [0.00, 0.01] [0.00, 0.01] [0.00, 0.01] Consumption 0.24 0.00 0.00 0.02 0.18 0.53 0.03 [0.18, 0.30] [0.00, 0.00] [0.00, 0.00] [0.00, 0.04] [0.11, 0.26] [0.46, 0.61] [0.02, 0.04] Real House Prices 0.05 0.01 0.00 0.87 0.04 0.02 0.01 [0.01, 0.09] [0.00, 0.02] [0.00, 0.00] [0.77, 0.97] [0.01, 0.07] [0.00, 0.04] [0.00, 0.02]
◮ Clearly the type of migrants affects the dynamics of migration shocks. When
◮ In this case, migrants are absorbed into the economy with very little aggregate
◮ If on the other hand, we believe that migration has an effect on the business
◮ The choice of χ affects the estimated model’s variance-covariance matrix and
2000 6000 10000 14000 18000
40000 120000 200000 280000 360000 440000 1963 1968 1973 1978 1983 1988 1993 1998 2003 2008 2013 2018 Construction workers (RHS) All groups (LHS)
◮ Migration focussed on skilled migration from early 1990s.
◮ A TFP shock is largely insensitive to the specification of the DSGE model, eg a
◮ In contrast, the effects of a migration shock are sensitive to specification of the
◮ One way to get a feel for the dynamics of the data is to run a simple SVAR using
◮ There is of course no guarantee that a DSGE model and a VAR will give similar
◮ The estimated DSGE model has a lot of structure and the variables we analyse
◮ We use a simple Cholesky decomposition that orders world GDP first, net
◮ We add the real exchange rate and real wages to our dataset.
−.002 .002 .004 −.001 .001 .002 .003 .01 .02 .03 −.01 .01 .02 .0002 .0004 .0006 −.02 −.01 .01 −.01 .01 .02 .03 −.001 .001 .002 10 20 30 40 10 20 30 40 10 20 30 40 Consumption GDP Real House Prices Investment Migration Real Exchange Rate Residential Investment Real Wages
◮ The qualitative response to a migration shock is the same. ◮ An increase in net migration is expansionary for GDP and its components. ◮ Net migration raises residential investment and real house prices. The latter rise
◮ Consistent with our model, the effective real exchange rate appreciates in
◮ The response of real wages to an increase in migration is not significant.
◮ Migration shocks clearly affect the business cycle, but they only explain about
◮ An unexpected increase in net migration is expansionary for the components of
◮ The real appreciation creates a positive wealth effects that enhances the marginal
◮ An increase in net migration raises both house prices and per capita residential
◮ The relative level of human capital has a material impact on the dynamics of the
◮ Our model suggests that the closer are new migrants to locals in terms of skill
◮ Our estimated model is qualitatively consistent with a simple structural VAR
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◮ The standard optimality condition for effective hours, capital, investment, and
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